Cambodia has begun it's official week of mourning after the body of former king Norodom Sihanouk returned to the kingdom yesterday.

Thousands lining the streets to pay tribute to the royal, who was seen as a father figure to many Cambodians.

The former king's body will lie in state at the palace for three months before an elaborate funeral.

The Golden Age

Son Soubert, a member of the Privy Council to Cambodia's current king Norodom Sihamoni, told Radio Australia's Connect Asia program he was moved by the reception the Cambodia people gave their former king.

"He's not only the figure of a father for the nation but he is also remembered for all that he has done, especially during the sixties when countries around Cambodia were engaged in the Vietnam war," Mr Son Soubert said.

"People of my age and even younger remember the age of development - what was known as the Golden Age."

Norodom Sihanouk

An Air China plane carrying the body of Cambodia's former king Norodom Sihanouk arrived at the airport in the capital Phnom Penh.

Mr Sihanouk died of a heart attack at the age of 89 in Beijing on Monday.

Tens of thousands of mourners had lined the streets of Phnom Penh to pay their last respects to the revered former king.

Mr Sihanouk's body was accompanied by his widow Queen Monique, son King Norodom Sihamoni and Cambodian Prime Minister Hun Sen.

Robed monks chanted prayers as the coffin was brought off the plane and decorated with white flowers.

Large portraits of a smiling Sihanouk were dotted along the main boulevards in the capital, filled up with throngs of people, young and old, wearing white shirts and holding small Cambodian flags as they waited under a sweltering sun.

"There are more than 100,000 people lining the streets. More are coming," government spokesman Khieu Kanharith told reporters at the airport, where people climbed on walls and car roofs to get a better view.

A convoy was set to take the coffin straight to the royal palace, where Sihanouk will lie in state for three months before an elaborate funeral for the ex-king, who remained popular after abdicating in favour of his son in 2004 citing old age and ill health.

The former king's body will then be cremated according to Buddhist ritual.

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